When three out of three reviewers for Positive Feedback all have their thumbs pointing upward about the piece under review, then something's going on. I have two of these for sale at $200 each. Sez one: "Its purpose is to restore body, uncover inner detail, lower the noise floor and improve imaging."
http://www.positive-feedback.com/ambackissues/HRS.htmFrom Greg Weaver's review on Soundstage: "The device is a class-A, solid-state gain stage that boosts the signal it is given by roughly 3dB (the specification sheet reads 2.7dB). Increasing the gain has the effect of lowering the noise floor and providing a more suitable signal for driving the input stage of a power amp. Additionally, it offers a nice high input impedance for those high-output-impedance preamps to be happy with and a nice low output impedance which will drive just about any amp quite well. . . . This is a 'must hear' component."
http://www.soundstage.com/revequip/weaver13.htm
